operator delete, operator delete[]

From Cppreference

C++ Standard Library
Language Utilities library Strings library Containers library Algorithms library Iterators library Numerics library Input/output library Localizations library Regular expressions library (C++11) Atomic operations library (C++11) Thread support library (C++11)
Utilities library
Dynamic memory management
Low level memory management Allocators allocator allocator_traits (C++11) scoped_allocator_adaptor (C++11) Uninitialized storage uninitialized_copy uninitialized_copy_n (C++11) uninitialized_fill uninitialized_fill_n Smart pointers unique_ptr (C++11) shared_ptr (C++11) weak_ptr (C++11) enable_shared_from_this (C++11) bad_weak_ptr (C++11) auto_ptr (deprecated) Garbage collection support declare_reachable (C++11) undeclare_reachable (C++11) declare_no_pointers (C++11) undeclare_no_pointers (C++11) pointer_safety (C++11) Miscellaneous pointer_traits (C++11) address_of (C++11) align (C++11) C Library malloc calloc realloc free
Low level memory management
Template:cpp/memory/new/sidebar content

Defined in header <new>
void operator delete  ( void * ptr );	(1)
void operator delete[]( void * ptr );	(2)

Deallocates memory, previously allocated by an allocation function, by either operator new or operator new[]. The ptr must be pointer, previously obtained by call to corresponding allocation function. For single allocated objects the first version of the expression must be used, whereas for arrays the second version must be used. Whether deallocation of memory, which was allocated by placement allocation function, needs to be performed and which deallocation function to invoke, is mandated by the particular allocation algorithm used by the program to allocate memory.

Contents 1 Replacing and overloading 2 Parameters 3 Return value 4 Exceptions 5 See also

[edit] Replacing and overloading

The program can implement both deallocation functions, which would then be used instead of the default implementations. Also, program can add versions of deallocation functions with different signatures. In this way it is possible to implement consistent interface to deallocate memory allocated by placement allocation functions.

The deallocation function can be replaced/overloaded in two ways:

in the global scope: in order to call it, the signature of the overloaded allocation functions must be visible at the place of deallocation, except for implicitly declared default deallocation functions. This allocation function will be used for all deallocations with corresponding parameters in the current program

in the local scope: the overloaded operator delete must be static public member function of the class. This deallocation function will be used only for deallocations of that particular class.

During compilation, each delete expression looks up for appropriate deallocation function's name firstly in the class scope and after that in the global scope. It can be instructed to skip the first step. Note, that as per overloading rules, any deallocation functions declared in class scope hides all global deallocation functions. For more information see delete expression.

[edit] Parameters

ptr

-

pointer to a memory area to deallocate

[edit] Return value

(none)

[edit] Exceptions

(none)

[edit] See also

operator new, new[]